So I was looking up different stages of transmissions when I ran across a site (Jacks Transmissions). Idk whether they're good or not but the main thing that caught my eye was the oils recommended for DSMs. It stated that, for transfer cases, don't use BG Synchroshift since it destroys your synchros and gears. I just wanted to know if this is true. It was referring to the EVO but I think it might have applied to DSMs also. Here is the exact quote if anyone is interested.

"DSM, 3S and EVO transmissions require 2.5-3 quarts of oil. For our DSM transmission rebuilds we recommend factory Mitsubishi 6-speed manual transmission gear oil from the 2005 Mitsubishi EVO MR. This is the best oil to use as it has the perfect blend of friction modifiers to keep the tranny shifting smoothly and prevent gear failure. Gear oil choice is very important and varies based on preloads and synchro blocker ring design, therefore it is strongly recommended that you stick with this fluid for our transmissions. If you are unable to locate Mitsubishi MR 6-speed oil from the Mitsubishi dealer, Redline MT90 gear oil will also work just as well. You can find this fluid here on our website.
For transfer cases and rear ends, use Redline Heavyweight Shockproof ONLY. It is especially important to use only Redline Heavyweight Shockproof fluid or Mitsubishi dealer t-case fluid in EVO transfer cases. DO NOT use Synchromesh, BG Synchroshift I or II, or Royal Purple. These fluids will destroy synchros and gears and void your warranty!"

I was thinking about getting Synchroshift II for my transmission which is why I'm asking. I think I've heard some people use it for transfer cases but I always questioned this. Either way, should I stay away from Synchroshift even if I wanted it for just my transmission? It's not a built transmission it's completely stock from what I know.

Also, does anyone have any suggestions on what oils they would recommend for my transmission and transfer case? Thanks in advance!

Redline, your Transmission and transfer case will thank you. I use Mt 90 for the tranny, and Heavyweight shock proof for the transfer case. you pretty much answered your own question...

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Lol I guess I did. I just see so many members on here that use BG Synchroshift and I was seriously so close to purchasing it until I accidentally ran over that site. So even on a stock tranny I should be using Redline MT90?

Wait so don't use MT-90 for the rear diff or do? Lol Calan you use Redline Heavy Shockproof for the rear diff. What would the difference be in using MT-90 for the rear diff as opposed to Redline Heavy Shockproof?

Your power levels and driving habits determine what fluid and weight to use in the trans. That Pennzoil stuff is like water. Your trans will shift quickly but won't offer much in terms of strength and protection. for higher power levels, def. want to go with something thicker. Most quicker guys run NEO gear oil in the trans (very high $$ stuff). I've used BGII + Heavyweight Shockproof in my trans for years and never had an issue. That's a few hundred 10 second passes in there too. I've never had a trans failure in my AWD car in the 10yrs I've owned it.

Your power levels and driving habits determine what fluid and weight to use in the trans. That Pennzoil stuff is like water. Your trans will shift quickly but won't offer much in terms of strength and protection. for higher power levels, def. want to go with something thicker. Most quicker guys run NEO gear oil in the trans (very high $$ stuff). I've used BGII + Heavyweight Shockproof in my trans for years and never had an issue. That's a few hundred 10 second passes in there too. I've never had a trans failure in my AWD car in the 10yrs I've owned it.

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Woah woah woah, maybe it's cause you got a 6 bolt XD haha just kidding. Jokes aside though, my 3rd gear grinds so I'm really trying to take it easy on the car since I JUST got it. I haven't done anything stupid with it so this is all thanks to the last owner. Should I go with the thicker stuff for the protection? I'm pretty set on Heavyweight Shockproof and the MT-90 only because I don't wanna risk anything on the tranny. It's not like I have a 10 sec car like you though . I mean it's basically stock besides the turbo (16G), intercooler, and BOV (1g).

Thanks for the input to all of you btw! It's definitely helped me a lot!

Sadly, no fluid will completely rid of the 3rd gear grind ... that's a tranny overhaul calling for you.

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I figured =/ I was reading some "miracle" stories of how Synchroshift II did the trick and that's why I was so close to getting it but thank god I did my research. It's not a terrible grind though. Only happens when I shift at high RPMs. It's easily avoidable by just putting it in slowly or by shifting at lower RPMs. Hopefully this means it doesn't need to be replaced soon seeing as I got other problems to fix =(

I have used BG Synchroshift II Full synthetic in the TRANSMISSION before without any problem when my car made about 300HP. And I currently am running Redline MT-90 in the Transmission now that I am making 450HP at the wheels as recommended by Jon at TRE.

I have always used Redline Heavy Weight Shockproof in the transfer case and rear end. Both of those need the extra protection offered by the heavier oil.

And I highly recommend that you stay away from BG Synchroshift I (the non-full synthetic). I had this in my transmission a while back and it cost me a few hundred dollars and pulling the transmission. I was having engine oil issues so I hooked up a pressure gauge to my oil filter housing and free reved the engine to see how high the pressure would climb. I did this with the transmission in neutral as I did not have all four wheels in the air. This means that the input shaft of the transmission was turning but no other parts in it were, including the front differential that pumps oil around the trans. At 5000RPM the transmission seized up and caused the engine to stall. The fifth gear hub had tried to weld itself to fifth gear. The BG Synchroshift did not even have enough film strength to protect the gears under no load.

I WOULD NEVER USE THE NON-FULL-SYNTHETIC BG IN ANY CAR I OWN NO MATTER THE POWER LEVEL!

In short here is what I recommend from my experiences with my DSM.
Transmission....
Redline MT-90 for a car with some mods and making over 300HP
Redline MT-85 for a car with under 300HP

Transfer Case and Rear End
Redline Heavy Weight Shockproof no matter how much power you make.

I have used BG Synchroshift II Full synthetic in the TRANSMISSION before without any problem when my car made about 300HP. And I currently am running Redline MT-90 in the Transmission now that I am making 450HP at the wheels as recommended by Jon at TRE.

I have always used Redline Heavy Weight Shockproof in the transfer case and rear end. Both of those need the extra protection offered by the heavier oil.

And I highly recommend that you stay away from BG Synchroshift I (the non-full synthetic). I had this in my transmission a while back and it cost me a few hundred dollars and pulling the transmission. I was having engine oil issues so I hooked up a pressure gauge to my oil filter housing and free reved the engine to see how high the pressure would climb. I did this with the transmission in neutral as I did not have all four wheels in the air. This means that the input shaft of the transmission was turning but no other parts in it were, including the front differential that pumps oil around the trans. At 5000RPM the transmission seized up and caused the engine to stall. The fifth gear hub had tried to weld itself to fifth gear. The BG Synchroshift did not even have enough film strength to protect the gears under no load.

I WOULD NEVER USE THE NON-FULL-SYNTHETIC BG IN ANY CAR I OWN NO MATTER THE POWER LEVEL!

In short here is what I recommend from my experiences with my DSM.
Transmission....
Redline MT-90 for a car with some mods and making over 300HP
Redline MT-85 for a car with under 300HP

Transfer Case and Rear End
Redline Heavy Weight Shockproof no matter how much power you make.

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Wow, I'm sorry to hear about your experience man. But look at you now I'm jealous! Haha. Thank you so much for sharing it though and giving me a very informative reply. Well I do have minor mods I guess but I'm not making 300 hp I was gonna use MT-90 anyways since my repair manual states that 75W-90 is one of the recommendations. I will definitely be using Redline Heavy Shockproof though that's for sure. I'll look into the MT-85 though. Thanks once again!